Tamper shield for spring bolt lock

ABSTRACT

A shield mountable to a door jamb to prevent tampering with the bolt lock of the door. The shield includes a mounting plate with a pair of walls integrally joined together at a right angle with each wall being fixedly secured to the door jamb. A third wall is integrally connected at an acute angle to one of the walls forming a stop to prevent passage of a burglary tool through the gap between the door and door jamb. A pair of end tabs are integrally mounted to the plate at a position above and below the bolt of the door. The stop and end tabs are spring biased to an original position and will return to the original position after the door is closed and opened. The outer distal ends of the stop and end tabs are beveled or turned inwardly to prevent the shield from snagging on the door as it is opened.

United States Patent [1 1 Sprunger July 23, 1974 1 TAMPER SHIELD FOR SPRING BOLT [21] App]. No.: 315,078

Primary ExaminerRobert L. Wolfe Assistant Examiner-Richard P. Tremblay Attorney, Agent, or FirmWoodard, Weikart, Emhardt & Naughton [57] ABSTRACT A shield mountable to a door jamb to prevent tampering with the bolt lock of the door. The shield includes a mounting plate with a pair of walls integrally joined together at a right angle with each wall being fixedly secured to the door jamb. A third wall is integrally connected at an acute angle to one of the walls forming a stop to prevent passage of a burglary tool through the gap between the door and door jamb. A pair of end tabs are integrally mounted to the plate at a position above and below the bolt of the door. The stop and end tabs are spring biased to an original position and will return to the original position after the door is closed and opened. The outer distal ends of the stop and end tabs are beveled or turned inwardly to prevent the shield from snagging on the door as it is opened.

2 Claims, 4 Drawing Figures 1 TAMPER SHIELD FOR SPRING BOLT LOCK BACKGROUND OF THE INVENTION 1. Field of the Invention This invention is in the field of guards or shields for door locks.

2. Description of the Prior Art A number of guards or shields have been provided to prevent tampering of a lock. Some of these prior art devices are shown in the following US. Pat. Nos.:

2,796,281 issued to Philpott;

3,154,343 issued to Devine;

3,524,669 issued to Reid; and

3,606,429 issued to Palmer. One guard for spring locks of interest is shown in the US. Pat. No. 3,149,870 issued to MacLaughlin et al.

In many of these prior art guards or shields, the guards or shields will become ineffective over a period of time due to the repetitive closing and opening of doors thereby permanently deforming the guard or shields. Disclosed herein is a guard which is con structed so as to return the movable portions of the guard to their original position even though the door which contacts the guard is repetitively closed and opened. Another problem with the prior art guards is that typically they will become snagged on the door when the door is opened thereby destroying the guard. Disclosed herein is a guard which will not snag on the door as the door is opened.

The guard disclosed in the MacLaughlin patent is designed for use with a lock having a spring loaded bolt which is mounted to the interior surface of the door. Of course, many doors are provided with locks which are built into the door in lieu of being mounted to the in side surface of the door. Thus, it is desirable to provide a guard which is usable with those doors having built in locks. Typically, a door jamb will have a right angle channel formed therein which seatingly receives the outside corner of the free swinging edge of the door. Disclosed herein is a guard which will mount to both surfaces forming the right angle channel in the door jamb.

SUMMARY OF THE INVENTION One embodiment of the present invention is in a guard for a spring lock mounted to a door including a mounting plate mountable to a door jamb in a gap between the jamb and the swinging edge of the door directly outdoors of a movable bolt of the lock, the plate having a stop at an acute angle with the plate preventing passage of a burglary tool through the gap from an outdoor side of the door to the bolt, the plate further including end tabs at an acute angle with the plate positioned above and below the bolt preventing access of a burglary tool to the bolt from above or below the stop with the plate, the stop and the end tabs comprising a single piece of metal wherein the improvement comprises, the plate has a main body with the stop and the end tabs spring biased away from the main body to an original position but resiliently yieldable to move adja cent the main body when the door is closed and then back to the original position when the door is opened, and the mounting plate further includes a first wall integrally connected lengthwise and perpendicular to the main body and fixedly securable directly to the door jamb to receive an outdoor surface of the door when closed and preventing entry of a burglary tool into the gap adjacent the bolt.

It is an object of the present invention to provide a new and improved tamper shield for use with a door lock.

It is a further object of the present invention to provide a tamper shield for a door lock which is constructed so as to have the movable portions of the shield to return to original positions even though the door is repetitively closed and opened.

Yet another object of the present invention is to pro vide a tamper shield for a door lock which will not snag on the door as the door is opened.

Related objects and advantages of the present invention will be apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective side view of a door jamb having the tamper shield mounted therein which incorporates the present invention.

FIG. 2 is a cross sectional view of the door jamb and shield shown in FIG. 1 receiving a door.

FIG. 3 is a cross sectional view taken along the line 3-3 of FIG. 1 and viewed in the direction of the arrows.

FIG. 4 is a cross sectional view taken along the line 4-4 of FIG. 1 and viewed in the direction of the arrows.

DESCRIPTION OF THE PREFERRED EMBODIMENT For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

Referring now more particularly to FIG. 2, there is shown a door 10 in abutting relationship with a door jamb 11. A spring loaded bolt 12 is retractable and is shown as projecting into cavity 15 of door jamb 11. Bolt 12 has a convex surface 13 which allows the bolt to be automatically retracted into the door as the door is swung to the closed position with surface 13 contacting strike plate 18 as the door is closed. Surface 14 of the bolt projects into cavity 15 and prevents the door from being opened unless the bolt is manually retracted into the door. Tamper shield 20 is shown mounted by fasteners into the right angle channel of door jamb 11 formed by surfaces 18 and 19. The outdoor surface 17 of door 10 is adjacent surface 19 when the door is in the closed position with strike plate 18 projecting inwardly of indoor surface 16 of door 10.

Tamper shield 20 is mountable to the door jamb in the gap which exists between the door jamb and the swinging edge of the door. The tamper shield is mounted directly outdoors of the movable bolt 12 and includes a first wall 21 and a second wall 22 integrally joined together at a right angle. Wall 21 is fixedly secured to surface 18 by fasteners 24 whereas wall 22 is fixedly secured to surface 19 by fasteners 23. Stop 27 is integrally connected to wall 21 and extends outwardly therefrom at an acute angle as shown in FIG. 4. Stop 27 prevents passage of a burglary tool through the gap between the door jamb and door from the outdoor side of the door to the bolt. In addition, a pair of end tabs 25 and 26 are integrally joined to wall 21 and extend outwardly therefrom at an acute angle being respectively positioned above and below bolt 12. Thus, end tabs 25 and 26 prevent access of a burglary tool to the bolt respectively from above and below stop 27.

Walls 21 and 22 along with stop 27 and end tabs 25 and 26 are produced from a single piece of metal. in one embodiment, the single piece of metal used to produce the tamper shield was 0.004 inches thick and was stainless steel. The tamper shield may be produced from a one piece stainless steel stamping die and can be produced with one progressive die. Since the tamper shield is produced from stainless steel, tabs 25 and 26 along with stop 27 will not be deformed as the door contacts the end tabs and stops during the repetitive opening and closing of the door. Thus, the improvement of the tamper shield includes stop 27 and end tabs 25 and 26 being spring biased away from wall 21 to the original positions with the door opened but resiliently yieldable to move adjacent to wall 21 when the door is closed and then back to their original positions when the door is opened.

Wall 22 is integrally connected lengthwise and perpendicular to wall 21 and receives the outside surface 17 of the door when the door is closed thereby prevent ing entry of a burglary tool into any gap normally provided between surfaces 17 and 19 and door and surface 18. ln many cases, the burglar will cut away the portion of door jamb 11 adjacent to surface 19 in order to then force a burglary tool straight inwardly towards bolt 12 through the gap between the door and surface 18. Wall 22 will reduce the possibility of cutting away the portion of the door jamb adjacent surface 19.

The outer end 34 of stop 27 and the outer ends 32 of tabs 25 and 26 are beveled or project inwardly to prevent the stop and end tabs from snagging on the door as the door is opened. That is, end 34 of stop 27 projects at an acute angle away from the main portion of the stop 27 and towards wall 22 whereas end 32 of tab 26 projects at an acute angle away from the main portion of tab 26 and towards wall 22. Likewise, the proximal ends of end tabs 25 and 26 and stop 27 are radiused to prevent snagging on door 10. As shown respectively in FlGS. 3 and 4, proximal ends 31 and 33 of end tab 26 and stop 27 are provided with a radius which is sufficiently small to prevent snagging but sufficiently large to prevent weakening of the metal during the formation of the radius. The outer distal ends of tabs 25 and 26 are radiused such as shown at location 30 for end tab 26. Likewise, the top portion 28 and bottom portion 29 of end tabs 25 and 26 are removed forming a catch or snag for the burglary tool as it is moved downwardly toward tab 25 or upwardly toward tab 26. The lengthwise junction between stop 25 and wall 21 extends from a position immediately adjacent and in line with the junction between stop 27 and wall 21 towards the indoor side of jamb l1 and away from wall 22. Likewise, the lengthwise junction between stop 26 and wall 21 extends from a position immediately adjacent and in line with the junction between stop 27 and wall 21 towards the indoor side of jamb 11 and away from wall 22. The outer distal edges of tabs 25 and 26 extend from a position immediately adjacent the junction between stop 27 and wall 21 to terminal end positions in spaced relationship to wall 21 forming gaps 28 and 29.

it should be noted that the material used to produce the tamper shield is not malleable but is resilient such as spring steel. Thus, the stop and end tabs are provided with a spring action. The leading edge of the door contacts and compresses the end tabs and stop each time the door is closed and releases the tension each time the door is opened. This guarantees a complete closure of the gap between the door and door jamb for the life of the tamper shield regardless of any shrinkage or warpage of a period of years. lt should also be noted that the tamper shield disclosed herein may be easily installed by an average person without exceptional mechanical skill.

While the invention has been illustrated and described in detail in the drawings and foregoing descrip tion, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.

The invention claimed is:

1. in a guard for a spring lock mounted to a door including a mounting plate mountable to a door jamb in a gap between said jamb and the swinging edge of said door directly outdoors of a movable bolt of said lock, said plate having a stop at an acute angle with said plate preventing passage of a burglary tool through said gap from an outdoor side of said door to said bolt, said plate further including end tabs at an acute angle with said plate positioned above and below said bolt preventing access of a burglary tool to said bolt from above or below said stop with said plate, said stop and said end tabs comprising a single piece of metal wherein the improvement comprises:

said plate has a main body with said stop and said end tabs spring biased away from said main body to an original position but resiliently yieldable to move adjacent said main body when said door is closed and then back to said original position when said door is opened; and,

said mounting plate further includes a first wall integrally connected lengthwise and perpendicular to said main body and fixedly securable directly to said door jamb to receive an outdoor surface of said door when closed and preventing entry of a burglary tool into said gap adjacent said bolt;

said stop includes a second wall with a proximal end connected to said mounting plate and a free outer edge projecting at an acute angle away from said second wall and towards said first wall preventing said second wall from snagging on said door as said door is opened;

said end tabs have main bodies with free outer edges projecting at an acute angle away from said bodies and towards said first wall preventing said tabs from snagging on said door as said door is opened, said plate has top and bottom outer edges, each end tab includes a proximal end integrally joined to said plate and a distal end extending from said plate adjacent said stop in a curve toward one of said outer edges of said plate but terminating in spaced relationship relative to said plate forming a notch in each end tab.

said main body includes fasteners extending therethrough into said first surface outdoors of said cavity, said first wall includes fasteners extending therethrough into said second surface. 

1. In a guard for a spring lock mounted to a door including a mounting plate mountable to a door jamb in a gap between said jamb and the swinging edge of said door directly outdoors of a movable bolt of said lock, said plate having a stop at an acute angle with said plate preventing passage of a burglary tool through said gap from an outdoor side of said door to said bolt, said plate further including end tabs at an acute angle with said plate positioned above and below said bolt preventing access of a burglary tool to said bolt from above or below said stop with said plate, said stop and said end tabs comprising a single piece of metal wherein the improvement comprises: said plate has a main body with said stop and said end tabs spring biased away from said main body to an original position but resiliently yieldable to move adjacent said main body when said door is closed and then back to said original position when said door is opened; and, said mounting plate further includes a first wall integrally connected lengthwise and perpendicular to said main body and fixedly securable directly to said door jamb to receive an outdoor surface of said door when closed and preventing entry of a burglary tool into said gap adjacent said bolt; said stop includes a second wall with a proximal end connected to said mounting plate and a free outer edge projecting at an acute angle away from said second wall and towards said first wall preventing said second wall from snagging on said door as said door is opened; said end tabs have main bodies with free outer edges projecting at an acute angle away from said bodies and towards said first wall preventing said tabs from snagging on said door as said door is opened, said plate has top and bottom outer edges, each end tab includes a proximal end integrally joined to said plate and a distal end extending from said plate adjacent said stop in a curve toward one of said outer edges of said plate but terminating in spaced relationship relative to said plate forming a notch in each end tab.
 2. The guard of claim 1 wherein: said door jamb has a first surface with a cavity thereon to receive said bolt and a second surface perpendicular to said first surface positioned adjacent said outdoor surface of said door when closed, said main body includes fasteners extending therethrough into said first surface outdoors of said cavity, said first wall includes fasteners extending therethrough into said second surface. 